I don't think german fighters are lacking as it is now, the 109 and 190 variants are pretty solid and even the 110 has 2 variants. Its a different story with the bomber set - and I do think an early ar and later war variant of a german bomber set would really make the entire german plane set more complete. I would rather see some tweaking of the 190 weights (the A5 should weight a fair bit less and so on), give the 110 C-2 or whatever some use, and give us more modifications to the german planesets. There was a lot of innovation there especially towards the end of the war.
As for Japanese planes, I really don't see any point in the early war birds, I know they would be great in FSOs and in EW/MW arenas - but thats because I use MA as the measure. Sure a few more light bombers perhaps for the Japanese - but really, an expanded gun package for the KI-84 and the really late war zero options would see more use.
But overall, I think the Soviet planeset is completely lacking right now - none of the LAGGs, no yak -3 (please, the yak 3) as fighters go, and I don't think there is a single russian bomber barring the IL2. There is a whole air-combat history there that simply has not been tapped and I really hope that the folks at HTC see this whole and work to fill it.
